When I say Kekkei Genkai, I mean solely the ones that require two seperate nature transformations combining together ex: Gale style, Lava Style, Boil Style
The reason I think this is because Sharingan originates from the Rinnegan. The Sharingan, while being inferior can copy all basic ninjutsu. I assume from that the Rinnegan also has the ability to copy ninjutsu but thanks to the fact that the user has access to all 5 nature transformations upon awakening; that and the assumed superior copying power of the Rinnegan the user could probably copy Kekkei Genkai.
The reason I think this is because Sharingan originates from the Rinnegan. The Sharingan, while being inferior can copy all basic ninjutsu. I assume from that the Rinnegan also has the ability to copy ninjutsu but thanks to the fact that the user has access to all 5 nature transformations upon awakening; that and the assumed superior copying power of the Rinnegan the user could probably copy Kekkei Genkai.